Fish soups with names similar to this one are common in the Mediterranean, with the type of fish and the seasoning varying with the locale. For example, Provençal cooks make bourride and serve it with the rust-colored sauce known as rouille, while Ligurian cooks make buridda and accompany it with fried bread. The burrida of the Balearics calls for skate in an allioli-enriched stock and thin slices of country-style bread.
Remove the central cartilage from the skate and cut the fish into 3-inch squares. Place in a shallow dish, sprinkle with salt, and drizzle evenly with the lemon juice. Let stand at room temperature for 1 hour. Rinse under cold running water and set aside.
In a large saucepan, combine the stock and the saffron and bring to a boil over high heat. Immerse the skate in the stock, decrease the heat to medium, and cook, uncovered, for 10 minutes, or until the fish is opaque at the center when tested with a knife tip. Using a slotted spoon, remove the skate from the pan, place on a platter, cover, and set aside. Increase the heat to high and boil the stock for 5 minutes longer.
Remove the stock from the heat and whisk in the allioli and parsley.
Place a slice of bread in each soup plate, place the skate on top, and cover with the stock. Serve immediately.